Based on a life course developmental perspective, this application proposes to use primary and secondary longitudinal data from three ongoing nationally representative birth cohort studies (born 2001, 1970, 1958; each n >10,000) to examine prevalence, predictors, and consequences of alcohol use from early adolescence through midlife. Specific aims of this developmental epidemiological application are to: (1) Examine variation in the prevalence of early alcohol initiation by conducting the first prospective national study of early alcohol use and attitudes starting in the age 11 survey of the 2001 Millennium Cohort Study (MCS), and testing theory- based hypotheses about child temperamental, cognitive, and family influences on early alcohol use in the MCS and the 1970 British Cohort Study (BCS) with structural equation models; (2) In the BCS and 1958 National Child Development Study (NCDS), examine how changes in work, family, and civic social roles across adulthood predict fluctuations in alcohol use and problem drinking (Role Socialization hypothesis), using fixed effects models to control for stable unobserved effects; and (3) Document long-term consequences of alcohol use for health and social roles in midlife (age 38/50 in BCS/NCDS) using propensity score models. J-shaped associations are hypothesized in which light-to-moderate alcohol use (relative to abstaining and to heavy drinking) predicts greater midlife health and role success (Consequences hypothesis). Analyses addressing all aims will use multisource-parent, teacher, medical, cognitive, self- report-and multi-wave longitudinal data to control for child and adolescent social and personal capital (Selection hypothesis) and test whether observed effects are buffered for those with greater capital (Selection x Role Socialization, Selection x Consequences hypotheses). Funds are requested to add measures of lifetime alcohol initiation, frequency of use and binge drinking, maximum quantity, positive and negative alcohol expectancies, perceived risk, and perceived peer pressure to age 11 MCS surveys, and to conduct secondary data analyses using already- collected longitudinal data from birth to age 7 (MCS), age 38 (BCS), and age 50 (NCDS). Long- term, the project aims to follow the MCS cohort through adolescence and beyond and the BCS and NCDS cohorts into older adulthood (as pivotal social roles continue to change and alcohol use/abuse consequences accumulate) to document population and sub-population patterns, effects, and variation in vulnerability to heavy and problem drinking. Prospective national data on drinking patterns across the life course, with appropriate controls for potentially spurious risk and protective factors and for conditional effects, are vital for (a) identifying developmental antecedents of vulnerability, (b) understanding mechanisms and ruling out spurious effects, and (c) informing and tailoring developmentally-appropriate programs and public health recommendations designed to decrease harms of alcohol abuse and dependence including disease, injury, and social role problems.